Materials Data on U2W2C3 by Materials Project

Abstract

U2W2C3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. U4+ is bonded in a pentagonal planar geometry to five C4- atoms. There are three shorter (2.44 Å) and two longer (2.49 Å) U–C bond lengths. W2+ is bonded to four C4- atoms to form a mixture of corner and edge-sharing WC4 trigonal pyramids. There are a spread of W–C bond distances ranging from 2.09–2.19 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to three equivalent U4+ and three equivalent W2+ atoms to form CU3W3 octahedra that share corners with six equivalent CU4W2 octahedra, edges with six equivalent CU3W3 octahedra, and a faceface with one CU4W2 octahedra. The corner-sharing octahedra tilt angles range from 40–60°. In the second C4- site, C4- is bonded to four equivalent U4+ and two equivalent W2+ atoms to form CU4W2 octahedra that share corners with twelve equivalent CU3W3 octahedra, edges with two equivalent CU4W2 octahedra, and faces with two equivalent CU3W3 octahedra. The corner-sharing octahedra tilt angles range from 40–60°.